Few images from
https://i.stack.imgur.com are not displaying.
For an example: This answer contains two images from
stack.imgur. One image is displaying properly the other one is not displaying. This issue is not only on Meta SO, it is on Meta ELU and on other sites too.
When opening the image it shows the warning as:
The image “https://i.stack.imgur.com/abcde.png” cannot be displayed because it contains errors.
Screenshot for reference: